Radio shack used to sell a large magnetic
read switch who's purpose was to detect an
open garage door. It was for use in an alarm
system.
The magnet would mount on top of the door,
and the switch itself just above the mangent
on the wall (when door was closed). It
suported a gap of 1-2 inches.
I got one, and it's been working great for
over a decade.
On my system, the "open door" detector as
well as the control of the button are
hard-wired (though I do run X10). Security
is the reason. If a neighbor stumbles on the
proper HC/Dev, I didn't want weird behavior.
Also, someone could plug in mini controller
to one of your outdoor outlets, and try all
the codes (if they know you're doing X10).
One scheme you might consder, I saw a few
years back was to use two modules. One
plugged into the other. That way the first
modules must be on to access the second one
(use different HC/Dev for each). So to
active the door open/close:
- turn module 1 on
-turn module 2 on
-wait a second
-turn module 2 off
-turn module 1 off.
Also, something you can consider if you can
detect when the door is open (hard wire of
X10), set a timer so that the door will close
after 10-20 minutes. I first set this up
when I lived in Minnesota and left the garage
open a couple night that we got snow.
